#include <stdio.h>
#include <string.h>
#include <stdlib.h>

/*
 *	Return the numeric value represented by the hex digit c.
 */
typedef struct assoc {
  char c;
  int  v;
} pair_t;

pair_t hexval[] = {{'0',0},{'1',1},{'2',2},{'3',3},{'4',4},
		   {'5',5},{'6',6},{'7',7},{'8',8},{'9',9},
		   {'a',10},{'b',11},{'c',12},{'d',13},{'e',14},{'f',15},
		   {'A',10},{'B',11},{'C',12},{'D',13},{'E',14},{'F',15}};
int getval (char c) {
  int i;
  for (i=0; i < sizeof(hexval); i++) 
    if (hexval[i].c == c) return hexval[i].v;
  return 0;
}

/*
 *	Return the integer representation of the four-character string of hex digits.
 */
int toInt (char in[]) {
  int k, val;
  for (val=0, k=0; k<4; k++) val = val*16 + getval(in[k]);
  return val;
}

char *opcodes[] = {"add","or","xor","and","addi","rotr","st","ld","ldi",
		   "uu","bneg","bz","jr","uu","uu","jmp"};

typedef unsigned int word_t;

int getopcode(word_t inst) { 
  return ((inst >> 12) & 0xF); 
}
int getop1(word_t inst){
  return (inst >> 8) & 0xF;
}
int getdest(word_t inst) {
  return (inst >> 4) & 0xF;
}
int getop2(word_t inst) {
  return (inst & 0xF);
}
int getim4(word_t inst) {
  return (inst & 0xF);
}

typedef void printFun_t(word_t instr, word_t pc);

void printRR(word_t instr, word_t pc) {
  printf("%4x: %04X %s $%d $%d $%d;\n", pc,instr, 
	 opcodes[getopcode(instr)], getdest(instr),getop1(instr),getop2(instr));
}

void printIM(word_t instr, word_t pc){
  printf("%4x: %04X %s $%d $%d %d;\n", pc,instr, 
	 opcodes[getopcode(instr)], getdest(instr),getop1(instr),getim4(instr));
}
void printMem(word_t instr, word_t pc){
  printf("%4x: %04X %s;\n", pc,instr, opcodes[getopcode(instr)]);
}
void printBr(word_t instr, word_t pc){
  printf("%4x: %04X %s;\n", pc,instr, opcodes[getopcode(instr)]);
}
void printRI8(word_t instr, word_t pc){
  printf("%4x: %04X %s;\n", pc,instr, opcodes[getopcode(instr)]);
}
void printJmp(word_t instr, word_t pc){
  printf("%4x: %04X %s;\n", pc,instr, opcodes[getopcode(instr)]);
}
void printUndef(word_t instr, word_t pc){
  printf("%4x: %04X %s;\n", pc,instr, opcodes[getopcode(instr)]);
}

printFun_t *printers[16] = {printRR,
			    printRR,
			    printRR,
			    printRR,
			    printIM,
			    printIM,
			    printMem,
			    printMem,
			    printRI8,
			    printUndef,
			    printBr,
			    printBr,
			    printMem,
			    printUndef,
			    printUndef,
			    printJmp};

int main (int argc, char* argv[]) {
  FILE *in;
  char line[256];
  int addr = 0;
  unsigned int inst;
  if (argc != 2) {
    fprintf (stderr, "wrong number of arguments (one expected)\n");
    exit (1);
  }
  in = fopen (argv[1], "r");
  if (in == NULL) {
    fprintf (stderr, "can't open %s\n", argv[1]);
    exit (1);
  }
  while (fgets(line, 256, in)) {
    inst = toInt(line);
    printers[getopcode(inst)](inst,addr);
    addr = addr+2;
  }
}